A:If not
B:Why not
C:If so
D:What’ more
如图为细菌的结构示意图,它与动植物细胞的主要区别体现于图中的哪一结构( )
已知a2﹣3a+1=0,求a2+1a2的值.
句子改错。
I have a headache I didn't sleep good last night.
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